Fiddled with a test doc. Changing it to autoplay="false" keeps it autoplaying. Removing the autoplay="true" part entirely stops the autoplay, and gives you a big play button on it so you know it's a video/animation.

As far as adding optional parameters, I am at a loss. Everything I can find says you'd just need to define multiple bbcodes. I don't know how quote and quote= work, quote= might just be its own defined bbcode. So maybe there would need to be two commands, one for autoplay and one for not, so that videos that are like videos can be handled appropriately, but webms and mp4s that are just replacing animated gifs don't need to be individually clicked on.

のほも is such a good word?? the concept is kind of hard to fully get across in translation, but basically it means a feeling of pure, deep, platonic affection, and i think thats beautiful

But it doesn't matter what's in the quotes; it doesn't get parsed. The part before the equals sign is the important part; you can put anything in the value. "disabled" or "foo" or "placeholder" or whatever.

disabled="true" is a common convention, but I think it's bad practice, for exactly the reason you've hit: it logically implies that disabled="false" would do the opposite. It doesn't. disabled="false" is exactly the same as disabled="true", disabled="yup", disabled="parking", or whatever you put in those quotes.

Same deal with autoplay, loop, allowfullscreen, or any other HTML property that's got a boolean value.

Confusingly enough, it doesn't work that way in some preprocessors. Earlier today I hit this exact problem because I was converting from a JSP-style

Just FYI this shit complete stops any media you have playing on an andriod device (podcasts, music) every single time you go to a page with a webm on it and god damn it if I havent had to restart my podcast a half a dozen times in the last 2 minutes for no good reason.

It's called TRUST Brentai. I TRUST that this guy is cursed to walk this life endlessly and unceasingly until the sun burns out and the planet collapes in on itself and all that remains is to float listlessly through the infinite nothing, screaming, never allowed to fucking die.